Abstract: A gas turbine engine casing includes a cavity 10 separated from the main flow 12 through the engine by an annular array of tip treatment bars 16. The tip treatment bars 16 are hollow which enables the bars to deform or break upon impact by a shed blade 4 or blade fragment. This allows the blade or blade fragment to pass through the tip treatment bars 16. Blade or blade fragments may then be contained within the cavity 10, or embedded in the casing 2, so preventing further damage to the engine. Entire blades, or large blade fragments, may be able to break through the tip treatment bars 16 and through the engine casing 2 so as to leave the engine entirely, causing the minimum of damage. The interiors of the tip treatment bars may be filled with a damping material, to minimize high cycle fatigue failure.

Abstract: A housing for a rotor of a turbomachine comprising, radially spaced inner and outer casings. The inner casing comprises a plurality of segments 20(a) to 20(e) each of which comprises one or more stator vanes 23. A first of the casings 19 has two or more axially spaced locating members 21,22 which co-operate with locating means 25,29 on the second of the casings 18 to locate the first casing 19 relative to the second casing 18. A first of the locating means 25 comprising a first surface 27 inclined to a direction extending axially along the second casing 18 and a second surface 28 that constitutes a sealing face. A first of the locating members 21 having a third surface 32 that confronts the first surface 27. In use, axial gas loads on the stator vanes 23 cause the first and third surfaces 27,32 to engage each other and slide along the incline to bring a fourth surface 33 on the member 21 into sealing engagement with the said second surface 28.